Signal processing device and signal processing method

ABSTRACT

Provided is a signal processing device including: a determination unit configured to determine a state of software associated with image processing on an input image signal indicating an image captured by a medical apparatus; and an output control unit configured to have a first processed image signal that is the input image signal on which image processing has been performed by the software selectively outputted, on the basis of a result of determination of the state of the software.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2015/054021 filed on Feb. 13, 2015, which claimspriority benefit of Japanese Patent Application No. JP 2014-082015 filedin the Japan Patent Office on Apr. 11, 2014. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a signal processing device and asignal processing method.

BACKGROUND ART

There has been developed a technique of redefining the circuitconfiguration of a field programmable gate array (FPGA). A techniquesuch as described in the following Patent Literature 1, for example, maybe mentioned as the technique of redefining, on the basis of a result ofcomparison between attribute information for defining a logic circuitread from the FPGA and the expected value thereof, the circuitconfiguration of the FPGA by updating the attribute information.

CITATION LIST Patent Literature

Patent Literature 1: JP 2008-015965A

SUMMARY OF INVENTION Technical Problem

Various devices such as those used for medical care, for example, suchas an endoscope, when performing image processing on an image signal,perform image processing on an image signal by image processinghardware, for example. On the other hand, software-based imageprocessing on an image signal is drawing attention because, for example,it is easier to change the content of image processing, and the costrequired for the change is lower. However, for example, software-basedimage processing on an image signal has not been sufficiently used incomparison with image processing on an image signal by image processinghardware.

The present disclosure proposes a novel and improved signal processingdevice and a signal processing method capable of outputting an imagesignal on which image processing has been performed by software, whensoftware-based image processing on an image signal is normallyperformed.

Solution to Problem

According to the present disclosure, there is provided a signalprocessing device including: a determination unit configured todetermine a state of software associated with image processing on aninput image signal indicating an image captured by a medical apparatus;and an output control unit configured to have a first processed imagesignal that is the input image signal on which image processing has beenperformed by the software selectively outputted, on the basis of aresult of determination of the state of the software.

According to the present disclosure, there is provided a signalprocessing device including: a software processing unit configured toexecute software associated with image processing on an input imagesignal that has been input; and a hardware processing unit having imageprocessing hardware that performs image processing on the input imagesignal. The hardware processing unit includes a determination unitconfigured to determine a state of the associated software, and anoutput control unit configured to have a first processed image signalthat is the input image signal on which image processing has beenperformed by the executed software selectively outputted, on the basisof a result of determination of the state of the software.

According to the present disclosure, there is provided a signalprocessing method including: a step of determining a state of softwareassociated with image processing on an input image signal that has beeninput; and a step of having a first processed image signal that is theinput image signal on which image processing has been performed by thesoftware selectively outputted, on the basis of a result ofdetermination of the state of the software.

Advantageous Effects of Invention

According to the present disclosure, it is possible to have an imagesignal on which image processing has been performed by softwareoutputted when software-based image processing on an image signal isnormally performed.

Note that the effects described above are not necessarily limited, andalong with or instead of the effects, any effect that is desired to beintroduced in the present specification or other effects that can beexpected from the present specification may be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram illustrating an example of imageprocessing in a case where image processing hardware is used and anexample of image processing in a case where software is used.

FIG. 2 is a block diagram illustrating an exemplary configuration of asignal processing device according to the present embodiment.

FIG. 3 is an explanatory diagram illustrating an exemplary hardwareconfiguration of a signal processing device according to the presentembodiment.

FIG. 4 is a timing chart illustrating exemplary processes performed by asignal processing device according to the present embodiment illustratedin FIG. 3.

DESCRIPTION OF EMBODIMENT(S)

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the drawings, elements that have substantially thesame function and structure are denoted with the same reference signs,and repeated explanation is omitted.

In addition, hereinafter, description will be provided in the followingorder.

1. Signal processing method according to the present embodiment

2. Signal processing device according to the present embodiment

(Signal Processing Method According to Present Embodiment)

Before describing the configuration of the signal processing deviceaccording to the present embodiment, the signal processing methodaccording to the present embodiment will be first described. In thefollowing, the signal processing method according to the presentembodiment will be described, taking as an example a case where thesignal processing device according to the present embodiment performsprocesses related to the signal processing method according to thepresent embodiment.

[1] Outline of the Processes Related to the Signal Processing MethodAccording to the Present Embodiment

In a case where image processing is performed on an image signal bysoftware, it is possible to perform more advanced image processing thanin a case where image processing hardware is used because, for example,it is easier to change the content of image processing, and the costrequired for the change is lower.

FIG. 1 is an explanatory diagram illustrating an example of imageprocessing in a case where image processing hardware is used and anexample of image processing in a case where software is used. “A” ofFIG. 1 indicates an example of image processing in the case where imageprocessing hardware is used and “B” of FIG. 1 indicates an example ofimage processing in the case where software is used.

As illustrated in “A” of FIG. 1, a development process which performsvarious processes relating to the development is performed on an imagesignal in the case where image processing hardware is used. On the otherhand, in the case where software is used, as indicated by “B” of FIG. 1,a noise suppressing process for reducing noise using a digital filter orthe like, a color correction process for correcting color, and ahigh-frequency emphasis process for emphasizing a region having afrequency higher than a pre-determined threshold value are performed onan image signal, in addition to the development process.

Here, it is also possible to implement the noise suppressing process,color correction process, high-frequency emphasis process and the likein the case where image processing hardware is used. However, it isdifficult to change the content of processing in the image processinghardware that performs the development process as indicated by “A” ofFIG. 1 and therefore it is very likely that new image processinghardware must be used in order to implement the noise suppressingprocess, color correction process, high-frequency emphasis process andthe like. Accordingly, changing the content of image processing is noteasy and also the cost required for the change is high in the case whereimage processing hardware is used. On the other hand, it is very likelythat changing the content of software-based processing is easier thanchanging hardware.

Note that the exemplary image processing in the case where imageprocessing hardware is used and the exemplary image processing in thecase where software is used are not limited to the example illustratedin FIG. 1. For example, each of the image processing hardware andsoftware may perform any image processing, or the image processinghardware and software may perform the same process.

As described above, in a case where image processing is performed on animage signal by software, it is very likely that more advanced imageprocessing can be implemented more easily than in a case where imageprocessing hardware is used. However, software-based image processing onan image signal has not been sufficiently used in comparison with imageprocessing on an image signal by image processing hardware. Therefore,in the case where image processing is performed on an image signal bysoftware, it is desired to ensure that an image signal obtained byperforming image processing on an image signal by software (referred toas “first processed image signal”, in the following) is an image signalobtained as a result of normal processing. In other words, it is desiredto ensure as high reliability as in the case where image processinghardware is used even in the case where image processing is performed onan image signal by software.

Therefore, as a process related to the signal processing methodaccording to the present embodiment, the signal processing deviceaccording to the present embodiment determines the state of the softwareassociated with image processing on an image signal that has been input(referred to as “input image signal”, in the following), and has a firstprocessed image signal selectively outputted on the basis of a result ofdetermination of the state of the software. The signal processing deviceaccording to the present embodiment has the first processed image signaloutputted when the state of the software is determined to be normal, ordoes not have the first processed image signal outputted when the stateof the software is not determined to be normal.

Here, image signals indicating a RAW image, for example, may be taken asan example of the input image signal according to the presentembodiment. In addition, the input image signal according to the presentembodiment may be a plurality of image signals indicating imagesrespectively corresponding to red (R), green (G) and blue (B), forexample.

In addition, image signals indicating an endoscope image captured by animaging device included in an endoscope such as a flexible endoscope ora surgical endoscope (rigid scope), for example, may be mentioned asinput image signals according to the present embodiment. Note that theinput image signals according to the present embodiment are not limitedto those indicating an endoscope image. For example, image signals suchas those described below may be mentioned as input image signalsaccording to the present embodiment.

-   Image signals indicating an image captured by an imaging device    included in a surgical microscope-   Image signals indicating an image generated by being captured by    various medical devices such as computed tomography (CT), magnetic    resonance imaging (MRI), positron emission tomography (PET),    ultrasonic diagnostic devices, or the like-   Image signals indicating an image captured by a broadcast station    camera-   Image signals indicating an image to be displayed on a display    device such as a broadcast station display device-   Image signals indicating an image captured by an imaging device such    as a digital video camera or a digital still camera, or an imaging    device included in a smart phone or the like

Input image signals according to the present embodiment may be, forexample, image signals generated by imaging devices such as thosedescribed above, or image signals read from a recording medium, theimage signals representing image data stored in the recording medium.

In addition, image processing software which performs a variety of imageprocessing, or system software relating to the operational environmentof the image processing software such as the operating system (OS), forexample, may be mentioned as software associated with image processingaccording to the present embodiment (may be simply referred to as“associated software”, in the following). The associated softwareaccording to the present embodiment is executed by hardware such as aprocessor having one, or two or more processor cores, for example. Acentral processing unit (CPU), for example, may be mentioned as theprocessor according to the present embodiment. The hardware such as aprocessor configured to execute the associated software according to thepresent embodiment is, for example, hardware capable of performingprocessing in accordance with the software to be executed, i.e.,hardware capable of performing processing generally.

In addition, the signal processing device according to the presentembodiment has the first processed image signal selectively outputted bytransmitting a control signal for controlling output of image signalsto, for example, an output unit (described below) included in the signalprocessing device according to the present embodiment, or an externaloutput device having a similar function to that of the output unit(described below).

For example, a signal (e.g., a high-level or low-level signal) whichturns on or off one, or two or more switching elements included in theoutput unit (described below) respectively may be mentioned as thecontrol signal according to the present embodiment. For example, ametal-oxide-semiconductor field-effect transistor (MOSFET) may bementioned as the switching element included in the output unit(described below).

[2] Exemplary Processes Related to the Signal Processing MethodAccording to the Present Embodiment

More specifically, the signal processing device according to the presentembodiment performs, for example, a determination process (1) and anoutput control process (2) as processes related to the signal processingmethod according to the present embodiment.

Note that the determination process (1) and the output control process(2) described below result from dividing the processes related to thesignal processing method according to the present embodiment into twoprocesses for convenience. Therefore, the processes related to thesignal processing method according to the present embodiment may berecognized as a single process combining the determination process (1)and the output control process (2) described below, or may be recognizedas two or more processes divided in an arbitrary manner. In thefollowing, the processes related to the signal processing methodaccording to the present embodiment will be described as being dividedinto the determination process (1) and the output control process (2).

(1) Determination Process

The signal processing device according to the present embodimentdetermines the state of the software associated with the imageprocessing on an input image signal.

(1-1) First Example of Determination Process: Determination Based onTest Result of Hardware that Executes Associated Software

The signal processing device according to the present embodiment causes,for example, the hardware that executes associated software to perform aset predetermined process. The signal processing device according to thepresent embodiment then determines the state of the associated software(simply referred to as “state of software”, in the following), on thebasis of a result of the predetermined process.

Here, a calculation process that performs a predetermined calculationmay be mentioned as the predetermined process according to the presentembodiment, for example. An arbitrary calculation such as “n=n+1” (n isan integer) may be mentioned as the predetermined calculation, forexample.

Note that the predetermined process according to the present embodimentis not limited to a calculation process. The predetermined processaccording to the present embodiment may be, for example, a process ofsending a response (e.g., ACK) to a response request including aresponse instruction. In the following, there is mainly mentioned a casewhere a calculation process is taken as an example for the predeterminedprocess according to the present embodiment.

In the case where the predetermined process according to the presentembodiment is a calculation process, the signal processing deviceaccording to the present embodiment determines that the state of thesoftware is normal when the result of the calculation process iscorrect. In addition, in the case where the predetermined processaccording to the present embodiment is a calculation process, the signalprocessing device according to the present embodiment determines thatthe state of the software is not normal when the result of thecalculation process is erroneous, or when the result of the calculationprocess is not available.

The signal processing device according to the present embodimentregularly or non-regularly transmits, to the hardware that executes theassociated software, a calculation request including a calculationinstruction to perform a predetermined calculation. In addition, when acalculation result for the calculation request is transmitted from thehardware that executes associated software, the signal processing deviceaccording to the present embodiment verifies the calculation result anddetermines the validity of the calculation result. Subsequently, in thecase where the calculation result for the calculation request is correct(in the case where the calculation result is valid), the signalprocessing device according to the present embodiment determines thatthe state of the software is normal. On the other hand, in the casewhere the calculation result for the calculation request is not acorrect result (in the case where the calculation result is not valid),or when the calculation result for the calculation request is notavailable, the signal processing device according to the presentembodiment does not determine that the state of the software is normal.

Additionally, in a case where the predetermined process according to thepresent embodiment is a process of sending a response for a responserequest, the signal processing device according to the presentembodiment regularly or non-regularly transmits a response request tothe hardware that executes the associated software. Subsequently, in acase where a response is returned from the hardware that executes theassociated software (or associated software that has been executed), thesignal processing device according to the present embodiment determinesthat the state of the software is normal. In addition, the signalprocessing device according to the present embodiment determines thatthe state of the software is not normal in a case where no response hasbeen returned from the hardware that executes the associated software(or associated software that has been executed) within a setpredetermined time.

Additionally, in a case where the hardware that executes associatedsoftware has a plurality of processor cores configured to execute theassociated software, the signal processing device according to thepresent embodiment causes some or all of the plurality of processorcores to perform a predetermined process. The signal processing deviceaccording to the present embodiment then determines the state of thesoftware on the basis of a result of the predetermined process in theprocessor core which has performed the predetermined process.

Here, in a case where some of the plurality of processor cores arecaused to perform the predetermined process, it is possible to reducetime and load relating to the determination process more than in a casewhere all of the plurality of processor cores are caused to perform thepredetermined process. Alternatively, in the case where all of theplurality of processor cores are caused to perform the predeterminedprocess, it is possible to enhance a determination precision of thestate of the software more than in the case where some of the pluralityof processor cores are caused to perform the predetermined process.

In a case where some or all of the plurality of processor cores arecaused to perform a predetermined process, when the state of thesoftware is determined not to be normal from the result of thepredetermined process performed by the processor cores, the signalprocessing device according to the present embodiment can take thefollowing measures, for example.

-   The first processed image signal processed by the processor core    corresponding to the result of determination that the state is not    normal is not outputted by the process (2) (output control process).-   The processor core corresponding to the result of determination that    the state is not normal is disabled and the associated software is    not executed.-   The first processed image signal processed by all the processor    cores including the processor core corresponding to the result of    determination that the state is not normal is not outputted by the    process (2) (output control process).-   All the processor cores including the processor core corresponding    to the result of determination that the state is not normal is    disabled and the associated software is not executed.

(1-2) Second Example of Determination Process: Determination Based onAuthentication Result of Associated Software

The signal processing device according to the present embodimentauthenticates the associated software, for example, and determines thestate of the software on the basis of the authentication result.

In a case where the authentication of the associated software has beennormally completed, the signal processing device according to thepresent embodiment determines that the state of the software is normal.On the other hand, in a case where the authentication of the associatedsoftware has not been normally completed, the signal processing deviceaccording to the present embodiment determines that the state of thesoftware is not normal.

In a case where the determination process according to the secondexample is performed, the associated software which has been normallyauthenticated is determined to be in a normal state. Therefore, it ispossible to prevent the first processed image signal that has beenimage-processed by invalid associated software such as, for example,tampered associated software from being outputted by the signalprocessing device according to the present embodiment performing thedetermination process according to the second example.

The signal processing device according to the present embodimentauthenticates the associated software by determining whether or not aresponse from the associated software is provided conforming to apreliminarily set authentication procedure.

As a specific example, the signal processing device according to thepresent embodiment transmits, to the associated software, a plain textwith a set predetermined length. The associated software performs apredetermined encryption process on the transmitted plain text using aprivate key held by the associated software, and transmits the encryptedtext resulted from encrypting the plain text to the signal processingdevice according to the present embodiment. The signal processing deviceaccording to the present embodiment decrypts the transmitted encryptedtext and determines whether or not the decrypted plain text matches theplain text which has been transmitted to the associated software. In acase where the decrypted plain text matches the plain text which hasbeen transmitted to the associated software, the signal processingdevice according to the present embodiment determines that the state ofthe software is normal. On the other hand, in a case where it isimpossible to decrypt the transmitted encrypted text, or in a case wherethe decrypted plain text does not match the plain text which has beentransmitted to the associated software, the signal processing deviceaccording to the present embodiment determines that the state of thesoftware is not normal.

Note that the processing according to authentication in thedetermination process according to the second example is not limited tothe example described above.

For example, the signal processing device according to the presentembodiment can authenticate the associated software by any procedurethat can authenticate the associated software.

In addition, the encryption process in the associated software mayinclude, for example, calculation depending on a value which can be usedby the signal processing device according to the present embodiment forauthenticating the associated software, such as a value indicating thesize of a program stored in the recording medium such as a storage unit(described below) included in the signal processing device according tothe present embodiment. In a case where the calculation depending on avalue which can be used by the signal processing device according to thepresent embodiment for authenticating the associated software isincluded in the encryption process in the associated software asdescribed above, it becomes possible to further enhance the strength oftampering prevention.

(1-3) Third Example of Determination Process: Determination Based onResult of Determining Validity of First Processed Image Signal

The signal processing device according to the present embodimentdetermines the validity of the first processed image signal, forexample, and determines the state of the software on the basis of aresult of determination of the validity. The signal processing deviceaccording to the present embodiment determines the validity of the firstprocessed image signal, for example, on the basis of pixel valuesincluded in the first processed image signal.

In a case where the first processed image signal is determined to bevalid, the signal processing device according to the present embodimentdetermines that the state of the software is normal. On the other hand,in a case where the first processed image signal is not determined to bevalid, the signal processing device according to the present embodimentdetermines that the state of the software is not normal.

The signal processing device according to the present embodiment doesnot determine that the first processed image signal is valid, forexample, in a case where the first processed image signal is like thefollowing description. It goes without saying that the example of notdetermining that the first processed image signal according to thepresent embodiment is valid is not limited to the examples describedbelow.

-   In a case where the first processed image signal indicates an    all-black image (in a case where all the pixel values indicated by    the first processed image signal are “0”)-   In a case where, for an input image signal indicating a video image,    the difference between a first processed image signal corresponding    to the preceding frame and a first processed image signal    corresponding to the current frame is equal to or larger than a set    threshold value (or in a case where the difference is larger than    the threshold value)-   In a case where, for an input image signal indicating an endoscope    image, pixel values other than the masked part of the endoscope    (e.g., circular part) are equal to or larger than a set threshold    value (or in a case where the difference is larger than the    threshold value)-   In a case where the first processed image signal has an impossible    pixel value-   In a case where the difference between the amount of characteristic    of the image indicated by the input image signal and the amount of    characteristic of the image indicated by the first processed image    signal is equal to or larger than a set threshold value (or in a    case where the difference is larger than the threshold value)-   In a case where the first processed image signal has an impossible    characteristic

Here, the following examples may be mentioned, for example, as specificexamples of the case where the first processed image signal has animpossible pixel value.

-   In a case where pixel value format is 10-bit data and the image data    includes 10-bit data and 6-bit invalid data, the 6-bit invalid data    turns out to be non-zero data despite that the 6-bit invalid data is    defined as “0”.-   When, in the aforementioned case, the position of the invalid data    switches between the least significant bit (LSB) side and the most    significant bit (MSB) side for each frame, the 6-bit invalid data    turns out to be non-zero data despite that the 6-bit invalid data is    defined as “0”.

In addition, the example described below may be mentioned, for example,as a specific example of the case where the image indicated by the firstprocessed image signal has an impossible characteristic.

-   In a case where the input image signal indicates an endoscope image,    the image indicated by the first processed image signal does not    have such a characteristic that “the central part is bright and the    peripheral part is dark” (an example of a predetermined    characteristic).

(1-4) Fourth Example of Determination Process

The signal processing device according to the present embodiment maydetermine the state of the software by performing each of two or moreprocesses from the determination process according to the first exampledescribed in the aforementioned (1-1) to the determination processaccording to the third example described in the aforementioned (1-3).

The signal processing device according to the present embodimentdetermines the state of the software associated with the imageprocessing on an input image signal by performing, as a determinationprocess, any of the processes from the determination process accordingto the first example described in the aforementioned (1-1) to thedetermination process according to the fourth example described in theaforementioned (1-4), for example.

(2) Output Control Process

The signal processing device according to the present embodimentselectively outputs the first processed image signal, on the basis of aresult of determination of the state of the software in the process(determination process) of the aforementioned section (1).

In a case where the result of determination of the state of the softwarein the process (determination process) of the aforementioned (1)indicates that the state is normal, the signal processing deviceaccording to the present embodiment outputs the first processed imagesignal. On the other hand, in a case where the result of determinationof the state of the software in the process (determination process) ofthe aforementioned (1) indicates that the state is not normal, thesignal processing device according to the present embodiment does notoutput the first processed image signal.

In addition, there may also be a case where image processing isperformed on an input image to be processed, for example, by imageprocessing hardware (image processing hardware included in a secondimage processing unit described below) included in the signal processingdevice according to the present embodiment, or external image processinghardware capable of communicating with the signal processing deviceaccording to the present embodiment. When, in the aforementioned case,the first processed image signal is not to be outputted, the signalprocessing device according to the present embodiment may output animage signal (referred to as “second processed image signal”, in thefollowing) obtained by performing image processing on an input imagesignal using the image processing hardware.

In a case where the image processing hardware always performs imageprocessing on an input image to be processed, the signal processingdevice according to the present embodiment switches the image signal tobe outputted from an output unit (described below) or the like to eitherthe first processed image signal or the second processed image signal bytransmitting, to the output unit (described below), the control signalin accordance with the result of determination of the state of thesoftware in the process (determination process) of the aforementioned(1). In other words, the control signal according to the presentembodiment serves as a switching signal for switching image signalsoutputted from the output unit (described below) or the like.

In a case where the result of determination of the state of the softwareindicates that the state is normal, for example, the signal processingdevice according to the present embodiment transmits, to the output unit(described below) or the like, a first control signal for outputting thefirst processed image signal without outputting the second processedimage signal. On the other hand, in a case where the result ofdetermination of the state of the software does not indicate that thestate is normal, the signal processing device according to the presentembodiment transmits, to the output unit (described below) or the like,a second control signal for outputting the second processed image signalwithout outputting the first processed image signal. Turning on or offone, or two or more switching elements included in the output unit(described below) or the like by the first control signal or the secondcontrol signal described above turns the image signal outputted from theoutput unit (described below) or the like into the first processed imagesignal or the second processed image signal.

Note that the image processing hardware may not always perform imageprocessing on an input image to be processed. In a case where imageprocessing on an input image to be processed is not always performed bythe image processing hardware, the signal processing device according tothe present embodiment causes the image processing hardware to performimage processing on an input image signal in a case where the state ofthe software is determined to be not normal in the process(determination process) of the aforementioned (1). The signal processingdevice according to the present embodiment causes the image processinghardware to selectively perform image processing on an input imagesignal by transmitting, for example, to a switching element forselectively inputting an input image signal to the image processinghardware, a signal for controlling the on- or off-state of the switchingelement.

In the case where the state of the software is determined to be notnormal, it is possible, for example, to reduce power consumptionconsumed by the image processing hardware, by the signal processingdevice according to the present embodiment causing the image processinghardware to perform image processing on an input image signal.

The signal processing device according to the present embodimentperforms, for example, the process (determination process) of theaforementioned (1) and the process (output control process) of theaforementioned (2) as processes related to the signal processing methodaccording to the present embodiment. The signal processing deviceaccording to the present embodiment determines the state of associatedsoftware in the process (determination process) of the aforementioned(1). Subsequently, in a case where the state of the software isdetermined to be normal in the process (output control process) of theaforementioned (2), the signal processing device according to thepresent embodiment outputs the first processed image signal (imagesignal on which image processing has been performed by software). On theother hand, in a case where the state of the software is not determinedto be normal in the process (output control process) of theaforementioned (2), the signal processing device according to thepresent embodiment does not output the first processed image signal.

Accordingly, the signal processing device according to the presentembodiment can output the image signal on which image processing hasbeen performed by software in a case where the software-based imageprocessing on an image signal is normally performed.

In addition, it is possible to output the image signal on which imageprocessing has been performed by software in a case where thesoftware-based image processing on an image signal is normallyperformed, and therefore it becomes possible to ensure as highreliability as in a case where image processing hardware is used(reliability comparable to that when image processing hardware is used),for example.

(Signal Processing Device According to Present Embodiment)

Next, an exemplary configuration of the signal processing deviceaccording to the present embodiment capable of performing processesrelated to the above-described signal processing method according to thepresent embodiment will be described. The following description takes,as an example, an exemplary configuration of the signal processingdevice according to the present embodiment in a case where processesrelated to the signal processing method according to the presentembodiment can be divided into the process (determination process) ofthe aforementioned (1) and the process (output control process) of theaforementioned (2).

FIG. 2 is a block diagram illustrating an exemplary configuration of asignal processing device 100 according to the present embodiment. Thesignal processing device 100 includes a hardware processing unit 102 anda software processing unit 104, for example.

In addition, the signal processing device 100 may include, for example,a control unit (not illustrated), a read only memory (ROM, notillustrated), a random access memory (RAM, not illustrated), a storageunit (not illustrated), an operation unit (not illustrated) which can beoperated by a user, a display unit (not illustrated) that displays avariety of screens on a display screen, and the like. The signalprocessing device 100 connects the respective components with each othervia a bus serving as a data path, for example.

The control unit (not illustrated), including a processor constituted bya calculation circuit such as a CPU, and various processing circuits,for example, serves to control the entire signal processing device 100.In addition, the software processing unit 104, for example, may serve asthe control unit (not illustrated) in the signal processing device 100.

The ROM (not illustrated) stores programs and control data such ascalculation parameters to be used by the control unit (not illustrated).The RAM (not illustrated) temporarily stores programs and the like to beexecuted by the control unit (not illustrated).

The storage unit (not illustrated), which is storage means included inthe signal processing device 100, stores a variety of data such as imagedata or various applications, for example. Here, a magnetic recordingmedium such as a Solid State Drive or a Hard Disk, a nonvolatile memorysuch as a flash memory, for example, may be mentioned as the storageunit (not illustrated). In addition, the storage unit (not illustrated)may be detachable from the signal processing device 100.

An operation input device such as a button, a direction key, a rotatableselector such as a jog dial, or a combination thereof, for example, maybe mentioned as the operation unit (not illustrated). In addition, adisplay device such as Liquid Crystal Display and an OrganicElectro-Luminescence Display (also referred to as Organic Light EmittingDiode Display (OLED display)) may be mentioned as the display unit (notillustrated).

[Exemplary Hardware Configuration of Signal Processing Device 100]

FIG. 3 is an explanatory diagram illustrating an exemplary hardwareconfiguration of the signal processing device 100 according to thepresent embodiment. The signal processing device 100 includes, forexample, an FPGA board 150, a CPU 152, GPU boards 154 and 156, a memory158, an 10 controller 160, a recording medium 162, and an interface 164.In addition, the FPGA board 150, the CPU 152, and the GPU boards 154 and156 are connected by a bus 166, for example.

The FPGA board 150, which corresponds to the hardware processing unit102 illustrated in FIG. 2, takes the initiative to perform the processesrelated to the signal processing method according to the presentembodiment. The FPGA board 150 includes, for example, an FPGA, an inputinterface to which an input image signal is input, and an outputinterface to which the first processed image signal or the secondprocessed image signal (may be collectively referred to as “output imagesignal”, in the following) is outputted. In the FPGA board 150, forexample, the FPGA corresponds to the hardware processing unit 102.

The CPU 152 and the GPU boards 154 and 156 correspond to the softwareprocessing unit 104 illustrated in FIG. 2. The CPU 152 and the GPUboards 154 and 156 execute a variety of software such as the associatedsoftware, for example, to perform various processes. FIG. 3 illustratesan example in which the CPU 152 includes eight core processors. Inaddition, the GPU boards 154 and 156 each include a graphics processingunit (GPU) and a dynamic random access memory (DRAM). FIG. 3 illustratesan example in which the GPU boards 154 and 156 each include 2048 coreprocessors.

The memory 158 stores a variety of data such as, for example, datacorresponding to an input image signal, and data corresponding to thesecond processed image signal. A dual inline memory module (DIMM), forexample, may be mentioned as the memory 158. The CPU 152 serves tocontrol writing and reading a variety of data to and from the memory158.

The 10 controller 160 serves to control transmission of signals amongthe CPU 152, the recording medium 162, and the interface 164, forexample.

The recording medium 162, which functions as a storage unit (notillustrated), stores a variety of data such as image data and variousapplications. Here, a solid state drive or the like, for example, may bementioned as the recording medium 162. In addition, the recording medium162 may be detachable from the signal processing device 100.

A universal serial bus (USB) terminal and a processing circuit, and alocal area network (LAN) terminal and a transmission and receptioncircuit, for example, may be mentioned as the interface 164.

The signal processing device 100 performs the processes related to thesignal processing method according to the present embodiment with theconfiguration illustrated in FIG. 3, for example. Note that the hardwareconfiguration of the signal processing device 100 according to thepresent embodiment is not limited to the configuration illustrated inFIG. 3.

For example, although FIG. 3 illustrates a configuration including theGPU boards 154 and 156, the signal processing device 100 according tothe present embodiment need not include the GPU boards 154 and 156 in acase where the CPU 152 has the function of a GPU.

In addition, the signal processing device 100 according to the presentembodiment may have any hardware configuration capable of performing theprocesses related to the signal processing method according to thepresent embodiment.

In the following, an exemplary configuration of the signal processingdevice 100 according to the present embodiment will be described,referring to the hardware configuration illustrated in FIG. 3 asappropriate.

Referring again to FIG. 2, an exemplary configuration of the signalprocessing device 100 will be described. The hardware processing unit102 performs, by hardware, various processes such as the processesrelated to the signal processing method according to the presentembodiment.

The hardware processing unit 102 includes, for example, a monitoringunit 110, a first function implementation unit 112 (second imageprocessing unit), and an output unit 114. The FPGA board 150 illustratedin FIG. 3, for example, may be mentioned as the hardware processing unit102.

The monitoring unit 110, which has a determination unit 120 and anoutput control unit 122, for example, takes the initiative to performthe processes related to the signal processing method according to thepresent embodiment.

The determination unit 120, which takes the initiative to perform theprocess (determination process) of the aforementioned (1), determinesthe state of the associated software. The determination unit 120determines the state of associated software to be executed in thesoftware processing unit 104.

The determination unit 120 determines the state of the associatedsoftware to be executed in the software processing unit 104 byperforming, for example, any of the processes from the determinationprocess according to the first example described in the aforementioned(1-1) to the determination process according to the fourth exampledescribed in the aforementioned (1-4).

Here, exemplary processing in the determination unit 120 will bedescribed, taking as an example a case where the signal processingdevice 100 has the hardware configuration illustrated in FIG. 3.

(a) Case of Performing Determination Process According to First Example

The FPGA of the FPGA board 150 regularly (e.g., about every 16 [msec])transmits a calculation request to software such as the OS running onthe CPU 152, for example. The software running on the CPU 152 returns acalculation result such as, for example, an incremented value to thecalculation request. The FPGA of the FPGA board 150 which has obtainedthe calculation result confirms whether or not the calculation resultmatches an expected value thereof. Confirming that the calculationresult matches the expected value ensures, for example, that softwaresuch as the OS running on the CPU 152 has not hung up, or the softwarealways returns a response to a calculation request (responding withoutexception).

Here, the CPU 152 illustrated in FIG. 3 has eight core processorsoperating in parallel, and the software such as the OS running on theCPU 152 allocates eight calculations to respective core processors toobtain eight calculation results. The CPU 152 then transmits the eightcalculation results to the FPGA of the FPGA board 150. Note that the CPU152 may confirm whether or not the eight calculation results matchexpected values thereof, and transmit the confirmation result ofoperation of the eight core processors to the FPGA of the FPGA board150.

In addition, in a case where a calculation request is transmitted, thesoftware such as the OS running on the CPU 152 transmits, to the GPUsincluded in the GPU boards 154 and 156, a calculation instruction toperform the calculation process indicated by the transmitted calculationrequest, for example. The GPUs illustrated in FIG. 3 each have 2048 coreprocessors operating in parallel, and the software running on the CPU152 causes the GPU to perform 2048 calculations, for example. Each ofthe GPUs included in the GPU boards 154 and 156 allocates 2048calculations to respective core processors, and transmits 2048calculation results to the CPU 152. The software running on the CPU 152confirms, for example, whether or not the 2048 calculation results matchexpected values thereof, and transmits the confirmation result of theoperation by the GPU to the FPGA of the FPGA board 150. Note that thesoftware running on the CPU 152 may transmit the calculation result bythe GPU to the FPGA of the FPGA board 150, for example, and the FPGA mayconfirm whether or not 2048 calculation results match expected valuesthereof.

In a case where the signal processing device 100 has the hardwareconfiguration illustrated in FIG. 3, performing, for example, theaforementioned process in the signal processing device 100 allows theFPGA of the FPGA board 150 functioning as the monitoring unit 110 toconfirm that the eight core processors of the CPU 152 and the 2048 coreprocessors of each of the GPUs included in the GPU boards 154 and 156are correctly responding.

Note that the example of the case where the determination processaccording to the first example is performed is not limited to theexample described above.

For example, the core processors of each of the GPUs included in the GPUboards 154 and 156 may include integer adders, integer multipliers,floating point adders, floating point multipliers, calculators offloating point special functions (such as trigonometric function,exponential function, and logarithmic function), texture buffers, or thelike. The calculation request according to the present embodiment mayinclude a calculation instruction to test whether or not a part or allof the aforementioned calculation resources are functioning. Testing theaforementioned calculation resources allows for further enhancing theprecision of determining the state of the software in the determinationprocess according to the first example.

In addition, in a case of testing the aforementioned calculationresources, each of the regularly (e.g., such as every 16 [msec])transmitted calculation requests may include a calculation instructioncorresponding to a part of the tests of calculation resources, insteadof a calculation instruction corresponding to all the tests ofcalculation resources. In a case where each of the regularly transmittedcalculation requests includes a calculation instruction corresponding toa part of the tests of calculation resources, it is possible to furtherenhance the precision of determining the state of the software in thedetermination process according to the first example, while reducing theload of the GPUs or the like included in the GPU boards 154 and 156.

(b) Case of Performing Determination Process According to Second Example

The FPGA of the FPGA board 150 regularly (e.g., such as every 3 [msec])authenticates software running on the CPU 152, for example.

For example, the FPGA of the FPGA board 150 transmits a plain text witha set predetermined length to the software running on the CPU 152. Thesoftware running on the CPU 152 performs a predetermined encryptionprocess using a private key held therein, and transmits to the FPGA ofthe FPGA board 150 an encrypted text obtained by encrypting the plaintext. The FPGA of the FPGA board 150 decrypts the transmitted encryptedtext, and confirms that the decrypted plain text returns to the plaintext transmitted to the software running on the CPU 152. Here, thestrength of tampering prevention can be further enhanced in a case wherethe procedure of encryption by the software running on the CPU 152includes a calculation depending on the size of the program stored inthe recording medium 162, for example.

(c) Case of Performing Determination Process According to Third Example

The FPGA of the FPGA board 150 determines the validity of thetransmitted first processed image signal, in a case where the firstprocessed image signal is transmitted from the CPU 152 and the GPUboards 154 and 156 functioning as the software processing unit 104.

The determination unit 120 performs, for example, any of the processesfrom the process described in the aforementioned (a) to the processdescribed in the aforementioned (c), or two or more processes from theprocess described in the aforementioned (a) to the process described inthe aforementioned (c). It goes without saying that the process in thedetermination unit 120 is not limited to the examples described above.

The output control unit 122 takes the initiative to perform the process(output control process) of the aforementioned (2). The output controlunit 122 has the first processed image signal selectively outputted, onthe basis of a result of determination of the state of the software inthe determination unit 120.

The output control unit 122 causes the output unit 114 to selectivelyoutput the first processed image signal by transmitting, to the outputunit 114, a control signal in accordance with the result ofdetermination of the state of the software, for example. In addition, ina case where the state of the software is determined to be not normal inthe determination unit 120, the output control unit 122 causes theoutput unit 114, for example, to output an image signal (correspondingto the second processed image signal) obtained by processing the inputimage signal in the first function implementation unit 112 describedbelow.

In addition, the output control unit 122 can also control the executionof the processing in the first function implementation unit 112described below, on the basis of a result of determination of the stateof the software in the determination unit 120, for example. The outputcontrol unit 122 causes the first function implementation unit 112 toperform processing in a case where the state of the software isdetermined to be not normal in the determination unit 120, for example.

The monitoring unit 110 has the determination unit 120 and the outputcontrol unit 122, for example, so as to take the initiative to performthe processes related to the signal processing method according to thepresent embodiment.

The first function implementation unit 112, which has image processinghardware, performs image processing on an input image signal by theimage processing hardware. Although the process indicated by “A” of FIG.1, for example, may be mentioned as image processing in the firstfunction implementation unit 112, image processing in the first functionimplementation unit 112 is not limited to the example indicated by “A”of FIG. 1.

The first function implementation unit 112 then transmits the imagesignal (second processed image signal) on which image processing hasbeen performed to the output unit 114.

The output unit 114 selectively outputs the first processed image signaltransmitted from the software processing unit 104 described below, onthe basis of the control signal transmitted from the output control unit122. In addition, the output unit 114 outputs the second processed imagesignal transmitted from the first function implementation unit 112 in acase where the first processed image signal is not to be outputted, forexample. In other words, the output unit 114 outputs the first processedimage signal or the second processed image signal as an output imagesignal, on the basis of the control signal transmitted from the outputcontrol unit 122.

For example, a switching circuit with any configuration capable ofoutputting the first processed image signal or the second processedimage signal on the basis of the control signal transmitted from theoutput control unit 122 may be mentioned as the output unit 114.

The hardware processing unit 102 includes, for example, the monitoringunit 110, the first function implementation unit 112 (second imageprocessing unit), and the output unit 114 so as to perform variousprocesses such as the processes related to the signal processing methodaccording to the present embodiment.

The software processing unit 104 executes the associated software. Forexample, the CPU 152 and the GPU boards 154 and 156 illustrated in FIG.3 may be mentioned as the software processing unit 104, and in thesoftware processing unit 104, the associated software is executed by theCPU 152 or the like so as to perform various processes.

For example, the software processing unit 104, which has the secondfunction implementation unit 116 (first image processing unit), performsimage processing on an input image signal by executing the software.Although the process indicated by “B” of FIG. 1, for example, may bementioned as the image processing in the second function implementationunit 116, image processing in the second function implementation unit116 is not limited to the example indicated by “B” of FIG. 1. The inputimage signal processed by the second function implementation unit 116corresponds to the first processed image signal.

Subsequently, the second function implementation unit 116 transmits theimage signal (first processed image signal) on which image processinghas been performed to the output unit 114.

The signal processing device 100 includes, as illustrated in FIG. 2, forexample, the hardware processing unit 102 that performs the processesrelated to the signal processing method according to the presentembodiment, and the software processing unit 104 that image-processes aninput image signal by executing software.

Here, exemplary processes performed by the signal processing device 100will be described. FIG. 4 is a timing chart illustrating exemplaryprocesses performed by the signal processing device 100 according to thepresent embodiment illustrated in FIG. 3. In FIG. 4, processes in thesoftware processing unit 104 are denoted as “SW” and processes in thehardware processing unit 102 are denoted as “HW”. Additionally, in FIG.4, the first function implementation unit 112 of the hardware processingunit 102 is denoted as “function 1” and the second functionimplementation unit 116 of the software processing unit 104 is denotedas “function 2”.

Taking as an example a case where the input image signal is an imagesignal indicating a video image, the hardware processing unit 102 (moreprecisely, the monitoring unit 110) and the software processing unit 104in the signal processing device 100 communicate with each other forevery one frame ( 1/60 [sec]), for example.

The determination unit 120 of the hardware processing unit 102 performs,for every one frame, the determination process (determination based ontest result) according to the first example described in theaforementioned (1-1) and the determination process (determination basedon authentication result) according to the second example described inthe aforementioned (1-2), for example. In addition, the determinationunit 120 of the hardware processing unit 102 performs, for example, thedetermination process (determination based on result of determination ofvalidity of first processed image signal) according to the third exampledescribed in the aforementioned (1-3) successively each time the firstprocessed image signal is obtained from the software processing unit104.

In a case where the result of determination of the state of the softwareindicates that the state is not normal (“NG determination” illustratedin FIG. 4) in the determination unit 120 of the hardware processing unit102, the output image signal is switched from the first processed imagesignal (“function 2 output” illustrated in FIG. 4) to the secondprocessed image signal (“function 1 output” illustrated in FIG. 4) fromthe frame next to the frame for which the result of determination of thestate of the software indicates that the state is not normal.

In a case where the output image signal is switched from the firstprocessed image signal to the second processed image signal, the signalprocessing device 100 may perform the following operations, for example.

-   Prompt the user to perform reactivation because the operation of the    software processing unit 104 has been incomplete (a visual prompt    using characters, images, light, etc., or an audio prompt using    sound (including music), etc.).-   Switch the output image signal from the second processed image    signal (“function 1 output” illustrated in FIG. 4) to the first    processed image signal (“function 2 output” illustrated in FIG. 4)    in a case where the result of determination of the state of the    software indicates that the state is normal.-   Prompt a user to contact a preset contact destination (e.g.,    software maker, or maker of the signal processing device 100, etc.)    because there is a possibility of tampering of software in a case    where the result of determination of the state of the software by    the determination process (determination based on authentication    result) according to the second example described in the    aforementioned (1-2) indicates that the state is not normal.-   Transmit information (data) indicating the possibility of tampering    of software to a preset transmission destination (e.g., an external    device such as a server of the software maker, or the server of the    maker of the signal processing device 100) in a case where the    result of determination of the state of the software by the    determination process (determination based on authentication result)    according to the second example described in the aforementioned    (1-2) indicates that the state is not normal.

The processes performed by the signal processing device 100 are notlimited to the examples illustrated in FIG. 4.

For example, although FIG. 4 illustrates an example in which theprocesses in the first function implementation unit 112 (“function 1”illustrated in FIG. 4) of the hardware processing unit 102 are alwaysperformed, the processes in the first function implementation unit 112of the hardware processing unit 102 may be started in a case where theresult of determination of the state of the software indicates that thestate is not normal (“NG determination” illustrated in FIG. 4).

The signal processing device 100 performs, for example, with theconfiguration illustrated in FIG. 2, the processes related to the signalprocessing method according to the present embodiment (e.g., the process(determination process) of the aforementioned (1) and the process(output control process) of the aforementioned (2)).

Therefore, in a case where the software-based image processing on animage signal is normally performed with the configuration illustrated inFIG. 2, for example, the signal processing device 100 can output animage signal on which image processing has been performed by software.

In addition, the signal processing device 100 can exhibit, for example,with the configuration illustrated in FIG. 2, the effect brought aboutby performing processes related to the signal processing methodaccording to the present embodiment such as, for example, thosedescribed above.

Note that the configuration of the signal processing device according tothe present embodiment is not limited to the configuration illustratedin FIG. 2.

For example, the signal processing device according to the presentembodiment can implement one or both of the determination unit 120 andthe output control unit 122 illustrated in FIG. 2 by a processingcircuit different from the hardware processing unit 102.

In addition, the signal processing device according to the presentembodiment need not include the first function implementation unit 112“in a case where, for example, image processing on an input image signalis performed in an external image processing hardware having a functionsimilar to the first function implementation unit 112”, or “in a casewhere a configuration is provided in which the second processed imagesignal is not outputted when the result of determination of the state ofthe software indicates that the state is not normal”.

In addition, for example, the signal processing device according to thepresent embodiment need not include the output unit 114 in a case wherethe first processed image signal is selectively outputted in an outputdevice having a function similar to the output unit 114. In theaforementioned case, the signal processing device according to thepresent embodiment controls the output of the output image signal in theoutput device by transmitting a control signal to the aforementionedoutput device, for example.

In addition, in a case where the image processing on an input imagesignal is performed by software in an external device having a functionsimilar to the software processing unit 104, for example, the signalprocessing device according to the present embodiment need not includethe software processing unit 104. In the aforementioned case, the signalprocessing device according to the present embodiment determines thestate of associated software to be executed in the aforementionedexternal device, for example.

In addition, as has been described above, the process (determinationprocess) of the aforementioned (1) and the process (output controlprocess) of the aforementioned (2) are processes obtained by dividingthe process related to the signal processing method according to thepresent embodiment for convenience. Therefore, the configuration forimplementing the process related to the signal processing methodaccording to the present embodiment is not limited to the determinationunit 120 and the output control unit 122 illustrated in FIG. 2 and mayhave a configuration in accordance with the way of dividing the processrelated to the signal processing method according to the presentembodiment.

Although the present embodiment has been described above taking a signalprocessing device as an example, the present embodiment is not limitedto such a configuration. The present embodiment can be applied tovarious devices capable of performing the processes related to thesignal processing method according to the present embodiment such as,for example, “various medical devices such as an endoscope, CT, MRI,PET, or ultrasonic diagnostic device”, “imaging devices such as abroadcast station camera, a digital video camera, or a digital stillcamera” “communication devices such as a cellular phone or a smartphone”, a tablet-type device, “computers such as a personal computer(PC), or a server,” a display device, a video/music playback device (ora video/music recording and playback device), a gaming machine, or thelike. In addition, the present embodiment can also be applied to aprocessing integrated circuit (IC) which can be built in theaforementioned devices, for example.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

In addition, the effects described in the present specification aremerely illustrative and demonstrative, and not limitative. In otherwords, the technology according to the present disclosure can exhibitother effects that are evident to those skilled in the art along with orinstead of the effects based on the present specification.

Additionally, the present technology may also be configured as below.

-   (1)

A signal processing device including:

a determination unit configured to determine a state of softwareassociated with image processing on an input image signal indicating animage captured by a medical apparatus; and

an output control unit configured to have a first processed image signalthat is the input image signal on which image processing has beenperformed by the software selectively outputted, on the basis of aresult of determination of the state of the software.

-   (2)

The signal processing device according to (1),

wherein the determination unit causes hardware executing the software toperform a predetermined process, and determines the state of thesoftware on the basis of a result of the predetermined process.

-   (3)

The signal processing device according to (2),

wherein, in a case where the hardware has a plurality of processorcores,

the determination unit causes a part of the plurality of processor coresto perform the predetermined process, and determines the state of thesoftware on the basis of a result of the predetermined process in a partof the processor cores.

-   (4)

The signal processing device according to (2) or (3),

wherein the determination unit determines that the state of the softwareis not a normal state when, in a case where the predetermined process isa calculation process, the result of the calculation process iserroneous, or when the result of the predetermined process is notavailable, and

the output control unit does not have the first processed image signaloutputted when the result of determination of the state of the softwareis not a normal state.

-   (5)

The signal processing device according to any one of (1) to (4),

wherein the determination unit authenticates the software and determinesthe state of the software on the basis of an authentication result.

-   (6)

The signal processing device according to (5),

wherein the determination unit determines that the state of the softwareis not a normal state when the authentication has not been normallycompleted, and

the output control unit does not have the first processed image signaloutputted when the result of determination of the state of the softwareis not a normal state.

-   (7)

The signal processing device according to any one of (1) to (6),

wherein the determination unit determines validity of the firstprocessed image signal on the basis of pixel values included in thefirst processed image signal, and determines the state of the softwareon the basis of a result of determination of the validity.

-   (8)

The signal processing device according to (7),

wherein the determination unit determines that the state of the softwareis not a normal state when the first processed image signal is notdetermined to be valid, and

the output control unit does not have the first processed image signaloutputted when the result of determination of the state of the softwareis not a normal state.

-   (9)

The signal processing device according to any one of (1) to (8), furtherincluding

a first image processing unit configured to perform image processing onthe input image signal by executing the software,

wherein the output control unit has the input image signal that has beenimage-processed in the first image processing unit selectively outputtedas the first processed image signal.

-   (10)

The signal processing device according to any one of (1) to (9),

wherein the output control unit, when not having the first processedimage signal outputted, has a second processed image signal that is theinput image signal on which image processing has been performed by imageprocessing hardware outputted.

-   (11)

The signal processing device according to any one of (1) to (10),further including

an output unit configured to selectively output the first processedimage signal on the basis of a control signal transmitted from theoutput control unit.

-   (12)

The signal processing device according to any one of (1) to (11),

wherein the image indicated by the input image signal is an endoscopeimage captured by an imaging device included in an endoscope.

-   (13)

The signal processing device according to (12),

wherein the determination unit determines validity of the firstprocessed image signal on the basis of a predetermined characteristicindicated by the endoscope image, and determines the state of thesoftware on the basis of a result of determination of the validity.

-   (14)

A signal processing device including:

a software processing unit configured to execute software associatedwith image processing on an input image signal that has been input; and

a hardware processing unit having image processing hardware thatperforms image processing on the input image signal,

wherein the hardware processing unit includes

a determination unit configured to determine a state of the associatedsoftware, and

an output control unit configured to have a first processed image signalthat is the input image signal on which image processing has beenperformed by the executed software selectively outputted, on the basisof a result of determination of the state of the software.

-   (15)

The signal processing device according to (14),

wherein the output control unit, when not having the first processedimage signal outputted, has a second processed image signal that is theinput image signal on which image processing has been performed by theimage processing hardware outputted.

-   (16)

The signal processing device according to (14) or (15),

wherein the determination unit causes hardware executing the software toperform a predetermined process, and determines the state of thesoftware on the basis of a result of the predetermined process.

-   (17)

The signal processing device according to any one of (14) to (16),

wherein the output control unit causes the image processing hardware toperform image processing on the input image signal when the state of thesoftware is determined not to be normal.

-   (18)

A signal processing method including:

a step of determining a state of software associated with imageprocessing on an input image signal that has been input; and

a step of having a first processed image signal that is the input imagesignal on which image processing has been performed by the softwareselectively outputted, on the basis of a result of determination of thestate of the software.

REFERENCE SIGNS LIST

-   100 signal processing device-   102 hardware processing unit-   104 software processing unit-   110 monitoring unit-   112 first function implementation unit-   114 output unit-   116 second function implementation unit-   120 determination unit-   122 output control unit

1. A signal processing device comprising: a determination unitconfigured to determine a state of software associated with imageprocessing on an input image signal indicating an image captured by amedical apparatus; and an output control unit configured to have a firstprocessed image signal that is the input image signal on which imageprocessing has been performed by the software selectively outputted, onthe basis of a result of determination of the state of the software. 2.The signal processing device according to claim 1, wherein thedetermination unit causes hardware executing the software to perform apredetermined process, and determines the state of the software on thebasis of a result of the predetermined process.
 3. The signal processingdevice according to claim 2, wherein, in a case where the hardware has aplurality of processor cores, the determination unit causes a part ofthe plurality of processor cores to perform the predetermined process,and determines the state of the software on the basis of a result of thepredetermined process in a part of the processor cores.
 4. The signalprocessing device according to claim 2, wherein the determination unitdetermines that the state of the software is not a normal state when, ina case where the predetermined process is a calculation process, theresult of the calculation process is erroneous, or when the result ofthe predetermined process is not available, and the output control unitdoes not have the first processed image signal outputted when the resultof determination of the state of the software is not a normal state. 5.The signal processing device according to claim 1, wherein thedetermination unit authenticates the software and determines the stateof the software on the basis of an authentication result.
 6. The signalprocessing device according to claim 5, wherein the determination unitdetermines that the state of the software is not a normal state when theauthentication has not been normally completed, and the output controlunit does not have the first processed image signal outputted when theresult of determination of the state of the software is not a normalstate.
 7. The signal processing device according to claim 1, wherein thedetermination unit determines validity of the first processed imagesignal on the basis of pixel values included in the first processedimage signal, and determines the state of the software on the basis of aresult of determination of the validity.
 8. The signal processing deviceaccording to claim 7, wherein the determination unit determines that thestate of the software is not a normal state when the first processedimage signal is not determined to be valid, and the output control unitdoes not have the first processed image signal outputted when the resultof determination of the state of the software is not a normal state. 9.The signal processing device according to claim 1, further comprising afirst image processing unit configured to perform image processing onthe input image signal by executing the software, wherein the outputcontrol unit has the input image signal that has been image-processed inthe first image processing unit selectively outputted as the firstprocessed image signal.
 10. The signal processing device according toclaim 1, wherein the output control unit, when not having the firstprocessed image signal outputted, has a second processed image signalthat is the input image signal on which image processing has beenperformed by image processing hardware outputted.
 11. The signalprocessing device according to claim 1, further comprising an outputunit configured to selectively output the first processed image signalon the basis of a control signal transmitted from the output controlunit.
 12. The signal processing device according to claim 1, wherein theimage indicated by the input image signal is an endoscope image capturedby an imaging device included in an endoscope.
 13. The signal processingdevice according to claim 12, wherein the determination unit determinesvalidity of the first processed image signal on the basis of apredetermined characteristic indicated by the endoscope image, anddetermines the state of the software on the basis of a result ofdetermination of the validity.
 14. A signal processing devicecomprising: a software processing unit configured to execute softwareassociated with image processing on an input image signal that has beeninput; and a hardware processing unit having image processing hardwarethat performs image processing on the input image signal, wherein thehardware processing unit includes a determination unit configured todetermine a state of the associated software, and an output control unitconfigured to have a first processed image signal that is the inputimage signal on which image processing has been performed by theexecuted software selectively outputted, on the basis of a result ofdetermination of the state of the software.
 15. The signal processingdevice according to claim 14, wherein the output control unit, when nothaving the first processed image signal outputted, has a secondprocessed image signal that is the input image signal on which imageprocessing has been performed by the image processing hardwareoutputted.
 16. The signal processing device according to claim 14,wherein the determination unit causes hardware executing the software toperform a predetermined process, and determines the state of thesoftware on the basis of a result of the predetermined process.
 17. Thesignal processing device according to claim 14, wherein the outputcontrol unit causes the image processing hardware to perform imageprocessing on the input image signal when the state of the software isdetermined not to be normal.
 18. A signal processing method comprising:a step of determining a state of software associated with imageprocessing on an input image signal that has been input; and a step ofhaving a first processed image signal that is the input image signal onwhich image processing has been performed by the software selectivelyoutputted, on the basis of a result of determination of the state of thesoftware.